I'm making a Uromastyx tank.

[kungfugi]

I have just started making a uromastyx tank and I'm not 100% what I am doing.
My plan is to have 1/3 of the tank raised up a few inches (3-4) and put Washed Play Sand in that part. With a log he can go in and climb on.
The rest will be Clay. Including a 4" wide tunnel at the front of the tank, and a slightly cooler home in the back.

Also if I made a background out of hard foam that I paint and glue sand to it, would the Uromastyx try to dig through it?

The picture I added is a mock up that I made with scrap wood. Although I might keep some of it there (covered with clay), there will be more clay and rocks.

So the top right is where the sand is going
The top left is the cooler hide. There will be a tunnel going in to it.
the bottom right is going to be a tunnel with a ramp into the sand.
On the left side there will be a few rocks to climb on too.